rasoul khosravi

In this research, we systematically reviewed the impacts of wildlife tourism on human-wildlife conflict. Our findings of the four thematic areas provided significant insights about the previous research. They indicated that “wildlife management” and “disturbance” are emerging fields of research in this domain, and more recently, themes emerged around “human-wildlife conflict,” “climate change,” and “ethnoprimatology.” Our literature showed that most of the wildlife tourism conflict involved wildlife behavior change (22.72%), crop riding (15.90%), and livestock depredation (9.09%), and few attempts have been made to explore the effects of wildlife tourism on other aspects of conflict such as attacks on human and negative attitudes towards wildlife. We provided significant insights about key areas of interest in wildlife tourism research, and it is expected that human-wildlife conflict will play a key role in generating future research on wildlife ecotourism research, which is necessary for human-wildlife coexistence.

Microgastrines are diverse group of endoparasitoid wasps attacking caterpillars (Lepidoptera). Despite their importance in biological control, there is still no consensus concerning the phylogeny relationships among taxa. Although previous phylogenetic analyses have advanced the overall understanding of phylogenetic relationships of Microgastrinae, the small numbers of sampled taxa have led to disagreement in taxonomic assignments. In the present study, we performed a molecular genetic survey using both mitochondrial and nuclear data, increasing the taxons' sampling, to clarify the generic relationships and improve the inferences of the taxonomic status within Microgastrinae. We reconstructed a phylogenomic tree of Microgastrinae with sequences that exist up till now, from fifty-five genera for COI and thirty genera for 28S rDNA, both new and from previous studies. Several species and genera have been sequenced for the first time. In this study, we identified some of the closest phylogenetic relatives of Microgastrinae genera by analyzing DNA sequences from the mitochondrial COI and 28S rDNA. Most clades of the current findings correspond to the latest morphological classification of Microgastrinae. New clades and several well-supported clades, conform to the most previously recorded clades and provide an increased understanding of the Microgastrinae evolution. Based on molecular examination, Pholetesor psedocircumscriptus Abdoli, 2019 is synonymized with Pholetesor circumscriptus (Nees, 1834).

Given the scarcity of data on river basins nationwide, numerous researchers turn to spatial analysis within a Geographic Information System (GIS) setting for hydrological studies and flood investigations. On that basis, identifying the most important factors influencing flood occurrence and severity, as well as building their sensitivity maps can be one of the most important solutions for flood reduction. Therefore, the objective of this study is to prepare a flood risk map in Bushehr province using machine learning techniques and to identify important factors affecting flood hazards.

In this study conducted in Bushehr province, we aimed to compare the effectiveness of three machine learning models: Support Vector Machine (SVM), Random Forest (RF), and Generalized Additive Model (GAM). Initially, layers of information influencing flood occurrence in the study area were identified. Each prepared map served as input for the models. Various layers such as slope, slope direction, elevation, distance to river, drainage density, lithology, land use, topographic wetness index, and vegetation cover index were prepared using ArcGIS and SAGA-GIS software, crucial for analyzing flood patterns. Using data from 925 flood locations, points were divided into two sets: 70% (645 points) for modeling and 30% (280 points) for evaluation. The effectiveness of the models was validated using Receiver Operating Characteristic (ROC) analysis.

The results indicated that among the ten main factors, height, rainfall, and lithology were the most important factors affecting flood occurrence, while slope and distance from the river had the least impact. Evaluating model accuracy using ROC revealed very good accuracy for the SVM model (0.86), generalized additive model (0.85), and RF model (0.88). Flood sensitivity analysis showed RF and GAM methods identified the highest area in the low susceptibility class, while the SVM method identified the highest area in the medium susceptibility class. Results indicated that 37.32% of the study area had low sensitivity, 26.01% had medium sensitivity, 12.42% had high sensitivity, and 24.42% were very sensitive to flood hazards. Also, two other models have had very good accuracy for flood modeling in the studied area. The ROC related to the RF model, SVM, and generalized collective model showed an accuracy of 88.5 for the RF model, 86% accuracy for the SVM model, and 85% accuracy for the generalized collective model.

This study concludes that integrating machine learning models, namely SVM, RF, and GAM, with GIS analysis holds tremendous potential for advancing our understanding of flood patterns in Bushehr province. Leveraging these tools allows for a deeper comprehension of flood dynamics, aiding informed decision-making and effective mitigation strategies. This approach marks a significant leap forward in proactively addressing flood challenges and fostering resilient flood management practices in Bushehr province.

In the comprehensive and integrated watershed management approach, watershed management has progressed from a mechanical and biological program to a comprehensive and integrated management system, through which we can guarantee human needs for the present and future generations in a reasonable way. Despite the fact that there is no doubt about the effectiveness of most watershed projects, the alignment of these projects with the goals of sustainable development needs to be evaluated.

We used IUCN method to assess sustainability of the watershed management plans in Sistan and Tol Heidari watershed of Jahrom County from 2005 to 2021. The most important strength of this method is simultaneous consideration of human and ecosystem factors. For this purpose, using opinion of experts, we determined criteria and indices in two main categories including ecosystem and human welfare. Finally, we selected three criteria and 15 indices for ecosystem section and four criteria and 13 indices for human section to assess watershed sustainability condition. The sustainability assessment of the watershed was performed with and without weighting the indicators and criteria.

The final score, according to the stability barometer respectively in the first method, was 66.30 before implementation and 71.33 after implementation. In the second method, the final score of 60.64 and 66.66 which indicates an upward trend in the level of stability and increase in the state of stability.

The results of the present study show that the watershed projects carried out in the region have been able to bring about a relative improvement in the ecological and economic-social conditions of the region.

Effective management of human-wildlife conflicts requires an understanding of risk perception, peoples’ responses to conflicts, as well as the impact of socio-economic and cultural factors on people's attitudes. We designed a questionnaire form to investigate the effect of each factor on human-brown bear conflicts in the areas with a high risk of conflict in Kamfiruz (Marvdasht county, Fars), during the peak conflict period (July to September), and evaluate the contribution of the effective strategies in mitigating conflicts. We used logistic regression to evaluate the factors affecting people's attitudes and also network analysis to survey the role of each factor in human-bear conflict and the importance of effective strategies in reducing conflict. The results showed that, according to the respondent's point of view, habitat loss and scarcity of natural prey, persecuting brown bears, and lack of sufficient knowledge about the species have the most centrality in the network. Also, among the suggested solutions by the respondent's, visual or auditory deterrents, trained dogs, compensation payments, insuring, and increasing natural prey’s population had the most centrality in the network, respectively. The results of the logistic regression showed that people who feel more eager when they see or think about bears have a more positive attitude toward the species. Also, people who like brown bears have a more positive attitude towards them. On the other hand, people who have a higher level of conflict with the species have a negative attitude towards it. According to the results, considering factors influencing natives' attitudes and engaging people in collaborative conservation programs have an important role in identifying effective and applicable solutions to mitigate human-brown bear conflicts.

Species distribution models (SDMs) are one of the most effective tools that determinethefactorsresponsible for shaping the geneticstructure of different taxa. These algorithms integrate the presence points and environmental predictors to estimate the probability of species occurrence across geographical areas. In the present study, we predicted the climate niche of Scorpio kruglovi(Scorpiones: Scorpionidae) in Iranusing eight uncorrelated bioclimatic variables and occurrence localities. This species was long considered a subspecies of S. maurusbutlater in 2015, itwas recognized as a distinct species. The area under curve (AUC) valueof 0.975indicated the excellent discriminative performance of the MaxEnt algorithm. The precipitation seasonality, minimum temperature of the coldest month,and precipitation of the coldest quarter had the highest percentage of contribution (63.3%)in building the model.The response curvessuggestedthatS. krugloviprefers the parts of Iran having 64-79%precipitationseasonality, 110-130 mm precipitation of the coldest quarter, and -7 to -13 0Cminimum temperature of the coldest month. Thesouthern half of the country was predicted as unsuitable habitats for the speciesoccurrence. Our findings confirmedtwo geographically distinctsuitable habitat patches in the northeastand northwest of Iran. Combining the obtained climate niche map withfuture genetic data is an effective approach for determining the boundaries of spatial patterns of intraspecific genetic variation.

Molecular data are powerful tools to resolve taxonomic problems. Each gene in each taxon shows a degree of variation through which we can understand phylogenetic relationships among different taxa. In this survey, the phylogenetic relationships within the tribe Bovini were reevaluated using 24 mitogenomes and cytochrome b (cytb), cytochrome c oxidase subunit 1 (cox1), 16S ribosomal RNA (16S rRNA), and NADH dehydrogenase subunit I (ND1) mitochondrial markers. We used all the gene sequences of extinct, domesticated, and wild species within the tribe Bovini. The phylogenetic trees were reconstructed using the maximum likelihood (ML) method. Based on the mitogenomes, the average base composition of mtDNA sequences was 27.1% T, 26% C, 33.5% A, and 13.4% G, showing a strong AT bias (60.6%). Our results revealed that the genus bison is not an independent taxon in the taxonomic rank of the genus and it is completely a paraphyletic taxon. Saola (Pseudoryx nghetinhensis) showed a sister relationship with other species belonging to the subtribe Bovina and it might be better to place this species within the subtribe Bovina. Also, in the mentioned subtribe, we distinguished three distinct monophyletic groups. In all of the phylogenetic trees, the subtribe Bubalina was a monophyletic taxon, and Syncerus caffer had a sister group relationship with other species belonging to the genus Bubalus. The obtained data should be taken into consideration in future conservation efforts for this tribe.

In recent years, increase in human-induced habitat disturbances and illegal hunting have led to reduction and isolation of the remaining populations of the brown bear. Despite its ecological importance on the health of natural ecosystems, there is a data scarcity on the genetic diversity and kinship relationships between individuals in the remaining populations. Advances in the DNA extraction from non-invasive samples has facilitated genetic studies on vulnerable species. In the present study, we used non-invasive sampling methods to assess genetic diversity indices, the probability of genetic identity among individuals, and the number of unique genotypes in the samples in order to estimate the minimum number of brown bears in the Parvar protected area. A total of 10 microsatellites were amplified using the extracted DNA from non-invasive samples. The overall observed heterozygosity, expected heterozygosity, and polymorphic information content were estimated 0.51, 0.57, and 0.5 respectively. The probability of identity indices (i.e. PID sib and PID unbiased) were 0.078 and 0.0032 respectively. Also, a total of 19 unique genotypes were identified. Our results showed that despite the low quality of non-invasive extracted DNAs, the amplified microsatellites had statistically effectiveness in identifying samples, assessing probability of genetic identity, and estimating minimum population size. The adopted approach in the present study can be used as a guideline for estimating population size and evaluating kinship relationships between individuals, especially for threatened carnivores, using non-invasive sampling approach.

In recent years, concerns have been raised about the presence of a wide range of drug substances and antibiotics in aquatic environments. Usually these materials are due to the inefficiency of conventional wastewater treatment technologies, From various routes such as agricultural runoff, direct discharge from urban wastewater treatment plants, human waste products, direct disposal of medical waste, industry, etc. into aquatic environments. The present study aims at the removal of penicillin G through electrofenton process in the aqueous solution.

The present study was conducted on laboratory scale in tanks made of glass using iron electrodes with useful volume 400 cc. The device is equipped with a flow rate regulator and voltage regulator to control these variables. Urban alternate current forms the input to the devices. The tank was filled with synthetic penicillin G with a concentration of 50-200 mg/L. The removal of penicillin G at potential 26V, the intensity of the 0.05-0.6A, Time 0-120 min, pH: 3-12 and the distance between the electrodes was measured in the range of 1-4cm.

The aim of present study was to the potential of the processes of electrofenton removal of penicillin G in aquatic environments. The results were pH of 3, the electric current density 0.6A, reaction time 20min, the concentration of antibiotic 50mg/l, and the distance between electrodes 1cm with concentration of H2O2 25mmol . in these circumstances, the results showed that electrocoagulation process is the ability to remove 100 percent of the pollutants.

The results of this study illustrate that electrofenton process with iron electrodes is cost-effective removal of organic compounds.

To use of beneficial effects (prevention of dental caries) and prevent all adverse effects such as dental and skeletal fluorosis, pregnancy outcomes, and blood pressure, the World Health Organization states concentration of fluoride in drinking water as a guideline 1.8-2 mg/L. The aim of this study was to determine the best deterministic and geostatistical interpolation model to investigate the spatial variability of fluoride in Yazd aquifer using a Geographic Information System.

In this cross sectional study, samples were collected from 24 wells, fluoride concentration was determined. To interpolate fluoride, deterministic and geostatistical methods was used in GIS software. Based on cross-validation criteria, best model interpolation was determined and zoning map prepared.

The mean fluoride concentration in the samples was equal to 0.2 ± 0.6 mg/L. The minimum and maximum fluoride concentrations respectively were 0.3 and 1.5 mg/L. by considering cross-validation criteria local polynomial Interpolation method (LPI) was selected as best model for fluoride mapping.

According to the results, In order to prevent the occurrence of side effects caused by a deficiency or excess fluoride on consumers’ health, it is necessary to conduct needful measures by responsible agencies.

Roasting methods due to environmental problems in the production of sulfur dioxide gas have led to further research on hydrometallurgy. In this research, the effect of effective acid leaching in the presence of oxidizing agents on sphalerite in the Aligudarz gol -zard mine was investigated. The purpose of this study is to recover acidic solution of zinc from sulfide raw ores using sulfuric acid and hydrochloric acid and the use of oxidants. In order to achieve the best operating conditions for further recovery, the parameters affecting the acid leaching process in the presence of oxides of hydrogen peroxide and potassium permanganate were investigated. Leaching in terms of acid concentration (0.5-3.5) molar, oxidizing materials concentration (0.01-0.05) volumetric, temperature (30-80°C), solid to liquid ratio (0.01-0.05) and stirring speed (300-800 rpm). During this process, the elemental produced sulfur was filtered, and also the zinc hydroxide was saparated by the addition of sodium hydroxide in the precipitation step by filtration. After the end of the research, sulfuric acid was observed with 3 molar concentration and 0.05 oxidation of hydrogen peroxide at 50 ° C and solids to liquid 0.01 and 700 rpm respectively. The optimum recovery of zinc solution was achieved in the optimum conditions and that the sulfuric acid oxidizing hydrogen peroxide was more efficient than hydrochloric acid and oxidizing potassium permanganate.

Faecal standing crop pellet group counts have been widely used in forested habitats to estimate deer population size. To convert pellet group density to deer density, Knowledge of disappearance rate of pellet groups is necessary. The disappearance rate of pellet groups may be different in different environments and can affect the accuracy of abundance estimation. We estimated decomposition and disappearance rate of Persian fallow deer (Dama mesopotamica) pellet groups in Dasht-e-Naz wildlife refuge, northern Iran, over a 12-month period. Labeling and monitoring pellet groups for decay was conducted at strip transects. Mean time ± SD to pellet group decomposition and pellet group disappearance were 94.84 ± 5.59 SE and 45.79 ± 2.71 days, respectively. Pellet groups persisted longest in summer and shortest in spring. The time to pellet group decomposition was significantly correlated with daily evaporation, mean daily air temperature and mean wind speed. The deposition of pellet groups became equal to their decay from 70-140th days and from 270-310th days since the start of the experiment suggesting a steady state system of the dung on the ground.

Long-term survival of Goitered gazelles in central Iran has been threatened because of isolation of existing populations and genetic threats. Effective management of these small and isolated populations needs to evaluate landscape connectivity among core habitat patches. In the present study, resistance surfaces were mapped as a function of twelve uncorrelated variables using species distribution algorithms. Given the limited empirical data of Goitered gazelle dispersal distances, we assessed different dispersal ability scenarios. Extent of core habitats, fracture zones, and dispersal corridors were identified using resistance kernel approach. Our finding showed that while gazelle population in Biduiyeh Protected Area has been isolated, there is relatively high dispersal rate among populations of Goitered gazelle in Mooteh National Park, Ghamishloo National Park, Kahyaz Protected Area, Kalmand-Bahadoran Protected Area and Kolah-Qazi National Park. Given the effect of roads and metropolises, functional connectivity between Kolah-Qazi and other populations is not possible. Based on genetic relationships and landscape connectivity results, we concluded that gazelle populations in Central Iran can be grouped into three separated subpopulations including 1- Biduiyeh P.A., 2-Kolah-Qazi N.P., and 3- gazelles in other protected areas. The obtained results show that integrated conservation management at landscape level need to be considered in maintaining gene flow among isolated and fragmented habitats.

The interactions between species and their environments can shape distribution of spatial genetic variations. Evaluation of niche overlap and environmental dissimilarity provides valuable opportunities to investigate how niche differences contribute to genetic divergence between populations that differ in their geographical distributions and environment conditions. Nowadays, the formerly large continuous populations of Goitered gazelle in Iran have been confined to fragmented habitats due to natural and anthropogenic factors. A statistical framework based on an ecological niche modeling at genetically management units (MUs) level was used to compare environmental niche and evaluate the effect of niche differentiations on genetic patterns of two management units of Goitered gazelle in Central Iran. We found low values of niche overlap between the management units. The niche equivalency hypothesis revealed that niche of MUs is more significantly distinct than expected by chance. Also niche similarity test for both comparisons falls within the 95% confidence limits of the null distribution. These findings demonstrate that the niche of two MUs is rarely identical, but they tend to be more similar than expected based on random predictions and environmental background, which they occur. We concluded that, besides landscape resistance and geographic distance, ecological niche isolation is another factor affecting the genetic structure of gazelle populations in Iran. Conservation planning of this vulnerable species should focus on isolated populations as separate management units and landscape linkages to maintain gene flow between the genetically similar populations.

The use of biodegradation methods by microorganisms in the removal of industrial dyes are widely considered owing to their high efficiency and compatibility to the environment. Therefore, this study aims to evaluate the biodegradation of methylene blue (MB) from aqueous solution by bacteria isolated from contaminated soil. This study was performed in laboratory scale on bacteria isolated and purified from contaminated soil with methylene blue. Initially, the bacteria was isolated from contaminated soil. Thereafter, medium containing 50, 100, 200, 400, 800 and 1000 mg/l of methylene blue, 50 ml of salt medium with glucose and 2.5 ml of Brain-heart infusion (BHI) medium containing bacteria were prepared. The results of dye removal were analyzed using UV/Vis spectrophotometer at 665 nm. The results of purification and identification of the bacterial species which degrade methylene blue indicated that Pseudomonas aeruginosa was the dominant bacteria. In this study, the removal efficiency of bacteria was attained from 82.25 to 97.82% with an increase in initial MB concentration from 50 to 200 mg/l. Nevertheless, with increase in MB oncentration from 200 to 1000 mg/l, removal efficiency was reduced to 43.08%. The optimum concentration of MB removal was 200 mg/l. It is evident from the results that the bacteria had used methylene blue as an auxiliary source of carbon apart from glucose. Finally, it can be concluded that P. aeruginosa is an appropriate candidate for the removal of methylene blue from the environment.

Context: Pharmaceutical products, particularly antibiotics, are new emerging contaminants that have caused much concern due to their accumulation in the environment and their other various adverse effects. Among such pharmaceutical products, metronidazole (MTN) is an important pollutant in the environment due to its broad use and resistance to biological breakdown. As a result, the need to control and eliminate this pollutant must be addressed more than ever. In this study, in addition to providing the most widely used methods for eliminating MTN antibiotic from the contaminated waste, the advantages and disadvantages of each method have also been analyzed.
Evidence Acquisition: This descriptive-interpretive study was conducted using documents and library resources.
There are several methods to remove antibiotics from aqueous environments, each having disadvantages along with advantages, which limit their application. Meanwhile, nanotechnology with its new solutions suggests that nano-sized substances can lead to more effective, cheaper, and more durable water treatment technologies, which can satisfy the needs of developing countries.
According to the results of this investigation, it appears that in recent years, nanotechnology and advanced oxidation process, which are based on the production of free and active radicals, especially OH0, have been effective because of their high oxidation power.

Previous studies have shown that the presence of nitrate in drinking water can cause several diseases especially in the infants, such as cancer and blue baby. The Environmental Protection Agency (EPA) has since adopted the 50 mg/l standard as the maximum contaminant level (MCL) for nitrate for regulated public water systems. This study aimed to evaluate the concentration of nitrate in the drinking water wells of Birjand, Iran, using inverse distance weighting (IDW) model and also using remote sensing (ENVI software) for studying the vegetation area. In this study, the average annual nitrate level in 2015 was measured from 19 wells around Birjand that were used as rural water supplies. For the zoning of nitrate concentration in the groundwater of Birjand, we used Arc GIS software by using IDW interpolation methods, and for studying the vegetation area and its effect on the groundwater quality we used Landsat Archive image (L4-5 TM sensor) and ENVI 4.7 software. The mean concentration of nitrate was 25.89 ± 12.33 mg/l in the groundwater. Nitrate concentration was more than the standard range (50 mg/l) according to the National Standard of Iran (No. 1053) in one well in the studied zone. Based on the information obtained from remote sensing, agricultural activities were an effective factor in increasing the concentrations of nitrate in the groundwater of the studied area.

Activated carbon is a most common adsorbent. By emerging of new technologies, the activated carbon production methods need to be improved. The aim of this study was producing powdered activated carbon from Peganum Harmala seed under ultrasound waves for activation and its application for chromium removal from aqueous solutions.
This experimental study was conducted in a batch reactor. The Peganum Harmala seeds were used for activated carbon production and Ultrasonic waves were used to activation. The BET test was done in order to determine of the specific surface area of produced activated carbon. The most important variables affecting the adsorption process were examined. For Cr(VI) determining UV/VIS Spectrophotometer T80 at a wavelength of 540 nm was used. Data analysis was performed by Excel software.
The BET test results showed that the specific surface area of produced ​​activated carbon is 442m2/g. The optimum pH of solution to adsorption process by both raw powder of Peganum Harmala seeds and produced powdered activated carbon adsorbents was equal 2. Adsorption data for both adsorbents were best fitted to the pseudo-second order kinetic and parameter of K2 for the produced powdered activated carbon was obtained two times more than K2 for raw powdered Peganum Harmala seed.
The results showed that ultrasound is very effective in activation of carbon and produced activated carbon have high adsorption rate and specific surface area, it and can be used as an appropriate adsorbent for removal of hexavalent chromium.

Because of the disadvantages of antibiotics in the ecosystem, it must remove before discharging wastewater containing them into the environment by an effective process. The aim of this study was cephalexin removal by local green montmorillonite loaded with TiO2 nanoparticles (TiO2/GLM) in the presence of potassium permanganate.
This experimental study was performed in batch. In this study, green montmorillonite found in the area of Ardabil sarcham used as base absorbent and to improve the efficiency of cephalexin removal stabilized TiO2 nanoparticles on it using potassium permanganate. Then, the most important variables affecting the process have been investigated. Scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR) tests used to investigate absorbent surface morphology and functional groups on the adsorbent respectively. The samples were analyzed by a spectrophotometer and data analysis was performed using Excel software.
SEM images showed that the absorbent surface has a high roughness and FTIR test showed change the functional groups because loading of TiO2 nanoparticles.the optimal condition was pH = 5, detention time= 60 min and adsorbent dose = 4 g/l for initial Cephalexin concentration of 25 mg/l. Also the results showed by decreasing temperature, removal efficiency was increased.
Due to the high efficiency of TiO2/GLM in the absorption of cephalexin as well as its morphology did not change after adsorption process, we can say that this adsorbent can be used as a cheap and efficient absorbent for the removal of cephalexin used

Background and The aim of this study was to investigate the efficiency of Fe3O4 nanoparticles synthesized by the chemical co-precipitation method for removal of black acid 1 from aquatic solutions.
In an experimental study, the Fe3O4 nanoparticle was synthesized by the chemical co-precipitation method using Fe and Fe solution in the presence of N2. The effect of different parameters including initial pH, adsorbent dose, contact time, initial dye concentration, temperature, and EC and also intervening variables such as nitrate, sulfate, fluoride, chloride and hardness were investigated. In addition, equilibrium data was fitted into Langmuir and Freundlich isotherm model, and pseudo-second order and pseudo-first order kinetic models.
We found that the adsorption capacities of nanoparticle increased when pH and adsorbent dose decreased. But the removal efficiency decreased by increase in temperature and dye concentration. Also intervening variables (nitrate, sulfate, fluoride, chloride, and hardness) were found to have low effect on decreasing the color absorption capacity by Fe3O4 nanoparticles. The removal of dye using Fe3O4 nanoparticle complies with Freundlich isotherm model (R2= 0.991). Also, the equilibrium adsorption data fitted with pseudo-second order kinetic (R2= 0.992).
This study showed that the Fe3O4 nanoparticle is highly capable of removing black acid 1 dye from aqueous solutions in low contact time. Therefore, the Fe3O4 nanoparticle can be considered as an effective adsorbent in dye removal.

Background and Natural organic matter in water resources (mainly caused by humic acid) leads to formation of THMs and HAAs. Removal of DBPs precursors from drinking water resources is the most important step to prevent from THMs formation. The aim of this study was to investigate the efficiency of modified nanoclay with EDTA and fresh nanoclay in adsorption of humic acid in aquatic solutions.
Characteristics and chemical structure of fresh and modified nanoclays were determined via scanning electronic microscope (SEM), BET, XRD, and FTIR techniques. HA concentration was determined by spectrophotometric method in 254 nm. Langmuir, Freundlich models and pseudo-first and pseudo second-order kinetics were used for adsorption isotherm and kinetics studies, respectively.
The XRD results showed that the distance between the layers increased after modification of nanoclay with EDTA. Also, BET analysis revealed that specific area of nanoclay increased from 13.02 to 28.36 m2/gr after modification. By decrease in pH the efficiency in removal of humic acid increased and in constant initial concentration of HA by increasing adsorbent dosage the adsorption capacity decreased. Adsorption of HA onto modified nanoclay and fresh nanoclay complies with Langmuir (R2=0.989) and Freundlich (R2=0.96), respectively. The pseudo-first order kinetic complies for both adsorptions.
This study showed that in acidic condition the modified nanoclay has an appropriate efficiency on HA adsorption.

Background and Among the numerous chemicals utilized in agriculture, 2,4-Dichlorophenoxyacetic acid (2,4-D) is widely used to control weeds. This herbicide is considered as a carcinogen and high toxic pollutant which is very difficult to remove due to its biological and chemical stability. This study aimed at photocatalytic degradation of 2,4-D using indium oxide nanoparticles in the presence of ultraviolet light.
This study was carried out in bench scale and batch system. The effect of operating parameters such as pH (2-11), contact time (5-240 min), catalyst dose (0.1-2 g/l) and initial concentration of herbicide (5-40 m/l) on the efficiency of the process were studied. The experimental data were fitted to a pseudo-first-order kinetic model.
Increasing the pH and initial concentration of herbicide led to reduced efficiency while increasing the contact time and catalyst dose increased the efficiency. The best result (70% efficiency) was achieved at pH 3, 1 g/l catalyst dose, 120 min contact time, and 5 mg/l initial concentration. The process data well followed the pseudo-first-order kinetic model (R2 = 0.915).
The results demonstrated that the photocatalytic process using indium oxide nanoparticles in the presence of ultraviolet light have a relatively good efficiency in removing 2,4-D.

Background and Azo dyes including Direct Blue 71 (DB71) are toxic, mutagenic and carcinogenic contaminants in effluents of industries. This study aimed to investigate the adsorption of DB71 from aqueous solution onto pistachio hull waste (PHW) as a low-cost adsorbent.
A series of experiments were performed via batch adsorption technique to examine the effect of the process variables such as contact time 0-210 minutes, initial dye concentration 10-100 mg/l, pH 2-12, adsorbent 0.05-1 g/l, and the processing temperature of 25, 40, and 50° C. The concentration changes of DB71 were measured using the colorimetric method by the spectrophotometer T80 ultraviolet/visible at the 587 nm wavelength. Moreover, The PHW was characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, Freundlich and Langmuir isotherm model, pHpzc and Brunauer–Emmett–Teller (BET) surface area analysis.
Maximum adsorption capacity was 90.48 mg DB71 per 1 g adsorbent at pH 2, DB71 100 mg/l, temperature 50° C, and time 210 minutes. In general, by increasing the adsorbent dosage, time, and processing temperature, the removal efficiency was increased; however, incrementing pH and dye concentration had a reverse effect. Maximum BET specific surface and total pore volume on the adsorbent were 1.04 m2/g and 0.0002 cm3/g, respectively. The Freundlich isotherm (R2 = 0.9912) model fits the equilibrium data better than the Langmuir isotherm (R2 = 0.9024) model. The adsorption kinetic was found to be well described by the pseudo-second-order model. Thermodynamic analysis indicated that the adsorption process is a spontaneous and endothermic process.
PHW can be used well as a low-cost surface adsorbent in the treatment of DB71 from aquatic environments.

Due to the ecological importance of the Shadegan wetland as a valuable international wetland and some studies reporting high mercury concentration in its water and bird's tissues, this study was done to measure and compare the concentration of accumulated mercury in different length groups of common carp muscle tissue and to determine the correlation of mercury concentration with morphological parameters such as standard length, total length and total weight.
In this cross-sectional study, 41 common carp fish were randomly captured in summer 2011 from the Shadegan wetland, and they were classified into three groups based on their lengths. Samples were prepared from their muscle tissues and mercury concentration was determined by Advanced Mercury Analyzer. The relation between mercury concentration in the samples and demographic characteristics was determined by Pearson’s Correlation Coefficient.
Mean (±Standard deviation) mercury concentration in groups of A, B and C were respectively 0.337±0.15, 0.556±0.21 and 0.798±0.19 µg gr-1 of dry weight basis. Comparison of mercury concentrations of muscle tissues among the three groups showed statistically significant difference (P=0.001); so that, mercury concentration was increased with increase of weight and length.
Mercury concentration in fish weighing more than 500 grams were higher than the limit allowed by WHO and EPA, it is necessary to be more careful about consuming this fish.